Hygienic Study on Container of Polystyrene (I)

Determination of Trace Amounts of Styrene Monomer in Milk Products

Abstract

The method for micro determination, on the level of ppb, of migrated styrene monomer from polystyrene containers for fermented milk was established.
Styrene monomer in fermented milks could be collected into a cooling traps of dry ice-methanol by steam distillation under reduced pressure. The concentration of styrene monomer of the fraction in the traps was determined by gas chromatography.
With this method, the recovery of styrene monomer added to fermented milk was found to be 88-95% in the range of 0.01 to 0.20 ppm, and the minimum detection limit was found to be 0.002 ppm.
Migration test of styrene monomer to fermented milk was examined using polystyrene containers including 5020 ppm of styrene monomer.
The migration of styrene monomer to fermented milks from the containers was increased with storage temperature and period. In the commercial fermented milks tested, styrene monomer could not be detected.